Homogenizer and mixer for liquids



L. L. BALASSA HOMOGENIZER AND MIXER FOR LIQUIDS 3 Sheets-Sheet 1 Dec.29, 1964 Original Filed Oct. 1, 1962 FIG INVENTOR. LESLIE L. BALASSADec. 29, 1964 1.. L. BALASSA HOMOGENIZER AND MIXER FOR uquzns INVENTOR.LESLIE L. BALASSA 3 Sheets-Sheet 2 Original Filed Oct. 1, 1962 Dec. 29,1964 L. BALASSA HOMOGENIZER AND MIXER FOR LIQUIDS Original Filed Oct. 1,1962 5 Sheets-Sheet 3 INVENTOR LESLIE L. BALASSA ATTORNEY United StatesPatent 9 Claims. ((11. 259-Q7) This invention relates to a mixing devicesuitable for many purposes, such as mixing, homogenizing, dispersing andpumping. It may be used both in laboratories and in production in thepreparation of emulsions, vegetable gum and starch dispersions, and forthe dispersion of finely divided solids in liquids, such as pigmentdispersions. This invention greatly improves the adaptability andetiectiveness of a mixing machine.

This is a continuation of application Serial No. 227,515 filed October1, 1962, now abandoned.

The machine of this invention mixes, blends, homogenizes, and dispersesemulsions, solutions and dispersions. Due to the unique construction ofthe turbine rotor and stator members of its operating head, themachineis particularly adapted top-recess emulsions and dispersions, which aremuch higher in viscosity and more highly thixotropic, more effectivelythan it has been possible to equal with other types of enclosed turbinedevices heretofore used.

The construction is such that the machine can be used as a closedturbine mixer or, by a single operation, as an efiicient open turbinemixer. By util zing certain adjusting means to decrease the spacehorizontally between the operating parts of the head, theirhomogenizingand dispersing action can be increased, and conversely, by increasingsaid spacing their purnping, blending, and mixing action can beincreased as well as the capacity of the machine.

With mixing devices of this type when a sleeve is fixed in positionsurrounding the rotor, the device is operated as a closed turbine unit,and the flow of liquid is through the sleeve along the axis of themixing device, which normally is vertically upwards. When the sleeve isremoved, the device is operated as an open turbine unit, and the entiremass of liquid in the vessel rotates about the axis of the devicecreating a vortex. The vortex incorporates air into the liquid which isoften undesirable, and reduces mixing efiiciency.

In the prior art etforts were made to correct the undesirable effects ofopen turbine operation. Baflies were introduced into the mixing vesselto control movement of the liquid about the axis of the mixing device.These bellies were costly, increased the difficulty and time of clean-upand interfered with the 'mixing eiiiciency of the device when it wasoperated as a closed turbine unit. Further, the mixing device had to besecurely clamped into position when. operated as an open turbine mixerbecause of its tendency to whip around under the pressure of the openrotor operating at high speed and under the influence of the rotatingliquid.

Heretoiore, efforts were made at easy convertibility of mixing devicesfrom open to closed turbine operation. One example is shown inapplicants copending application, Serial No. 84,821, which has aremovable sleeve.

While the construction taught in that application wa a great improvementover the art, it was practicable'only with devices that could be removedfrom the mixing vessels. Removing or replacing the sleeve after anoperation to convert the device is messy and wasteful of material. I V

Thepresent invention overcomes these shortcomings in prior art devicesin an easy, facile manner. In accordance with the present invention, amixing device can be converted from a closed turbine operation to anopen turbine operation or vice versa, by controls remote from the mixinghead, without removing'the head from the mixing vessel. Thus, thelargest units, including those fixed permanently into the mixing vesselcan be converted easily from one to the other type of operation quicklywith little down time.

Another advantage of the present invention is when the unit is operatedas an open turbine operation, bafiles are automatically provided whichprevent the formation of a vortex and direct the flow of liquid towardthe periphery of the mixing vessel and a quantity of liquid between thestator vanes. This muiti-directional flow provides excellent mixingcharacteristics and eliminates any stagnant pools of material in themixing vessel.

Other objects and advantages of the invention will be apparent from thefollowing description and accompanying drawings, in which drawings:

FEGURE l is a side elevational view of a mixing machine embodying theinvention in the closed position;

FKGURE 2 is an enlarged sectional view ofthe vane operating mechanism ofthe machine taken along lines 2--2 of FlGURE 1;

FIGURE 3 is an enlarged crosseectional view of the operating head takenalong lines 3-3 of FIGURE 1;

FIGURE 4 is an enlarged fragmentary detail view in elevation of theoperating head showing the vanes in open position; 7

FIGURE 5 is an enlarged view showing the vanes of the operating head inthe open position; and

FEGURE 6 is a dir'ierent embodiment of the operating head.

Referring to the drawings, and particularly to FIGURE 1, the mixingmachine comprises a motor it mounted in an upright position with itslower end attached to a motor support bracket 12. Bracket 12 may beclamped or held vertically in any convenient manner not shown. Dependingdownwardly from bracket 12 are a series'of guide or support rods 16,there being four rods shown in the drawings, with their lower endssecured to an operating head 20 relatively remote from the motor and invertical alignment therewith.

Motor 1% has a drive shaft 22, and beneath in vertical alignmenttherewith is a driven mixer shaft '24. The lower end of drive shaft 22is connected to the upper end of the mixer shaft 24 by a coupling 26.

' Operating head 26? comprises a stator 3d, and a turbine rotor 46.Stator 36 consists of a central hub part and a plurality of spokes orvanes 31 integral therewith and radiating outwardly therefrom, withtheir outer ends open, and being suitably spaced apart to provide whatmay be termed jet openings therebetween forming passage- Appropriatemembers of ways for the fluid solution. spokes 31 are secured to thelower ends of guide rods 16, in any convenient manner, such as bythreaded engagement, s ecial fittings, clamps, etc.

The lower end of shaft 24 is stabilized by being slidably journalled inthe hub of'stator fit? as shown in PEG- URE 4, and turbine rotor 49',which is preferably stainless steel, is attached to shaft 2 5 in closeproximity to stator 30. As shown, rotor 49 is attached to shaft 24 by anut 41 acting against a shoulder of shaft 24. Rotor tilt is precisionengineered, tempered and'balanced for high.

of stator 30, and their trailing edges 48 are also parallel withsurfaces 32 but closely associated therewith to provide a hydraulicshear when the blades 42 are swept across surfaces 32. Thisconfiguration of blades 42 forms a wedge-like area between the bladesand surfaces 32 which progressively diminishes rapidly as the trailingedges 48 approach during the whirling of rotor 40. It will be understoodthat simultaneously the leading edges sweep through the fluid, so thatthe latter will be directed vertically upward .by the pitch of blades,and fed through the hydraulic shear of the trailing edges, and onthrough the jet openings between adjoining spokes 34.

Surrounding rotor 40 is a sleeve 60 shown best in FIGURES 1 and 3. Asshown, sleeve 60 is open ended and has a generally square outer shapehaving four sides, 62, 64, 66 and 68. The inner surfaces of sides 62,64, 66 and 68 are curved to form a cylindrical surface about rotor 40,as best seen in FIGURE 3. Sleeve 60 may take other shapes as will beindicated hereafter. As

shown, sides 62, 64, 66 and 68 taper inwardly at their lower edges. Nut41 securing rotor 40 to shaft 24 extends below the lower edges of sides62, 64, 66 and 63 to provide space for fluid to pass when nut 41 restson the floor or bottom of the container for preventing the operatinghead from being sucked against the bottomof the container, not shown,during operation.

The operating head of the present invention may be converted into anopen turbine mixer in a simple, facile manner. Each of sides 62, 64, 66and 68 is pivotally mounted to a selected radially extending statorspoke 31, as best seen in FIGURE 5. Extending radially outwardly fromthe hub of stator 36 are four arms 72, 74, 76, and 78, which supportsides 62, 64, 66 and 68 respectively, when they are in the closedposition, as best seen in FIGURE 3.

Attached to the pivoting mechanism of sides 62, 64, 66, and 68 arevertically extending rods 82, 84, 36, and

, 88 respectively. As shown, these rods are coupled to theircorresponding sides by a pin to allow for easy disassembly. Rods 82, 84,86, and 88 extend vertically upward through motor bracket 12.

Rods 82, 84, 86, and 88 are preferably rotated'simultaneously and in thesame direction in an are sufficient to pivot each of sides 62, 64, 66,and 68 of sleeve 60 substantially an equal amount. One manner ofaccomplishing this is shown in FIGURE 2. Disposed between consecutivesprocket wheelsmounted on the ends of rods 82,

84, 86, and 88 are sprocket wheels 99, 92, 94, and 96,

respectively. These sprocket wheels are attached to their respectiveshafts in any convenient manner, such as by keys or splines. Rods 82,84, 86, and 88 are journalled on a support plate 98 mounted on bracket12. Disposed v between adjacent sprocket wheels is an idler wheel. In-

terposed between sprocket wheels 90 and 92 is an idler.

is an idler wheel 104, and between sprocket wheels 96 r and 90. is anidler wheel 166. Engagingthe sprocket wheels and idler wheels in amanner as shown in FIG- URE 2 is a continuous chain belt 1168. Belt 163is rotated by means of a sprocket gear 116 coupled to a .hand wheel 112Rotation of hand wheel 112, counter clockwise, as shown in FIGURE 2,actuatcs chain belt 108, as shown by arrows 114 and 116. It is seen thatsprocket wheels 90, 92, 94 and 96 all rotate in the same direction,counter clockwise, which in turn rotates their corresponding rods 82,84, 86, and '38 counter clockwise, so that sleeve sides 62, 64, 66, and68 respectively, are opened to the position shown in FIGURE 5. While. ahand wheel mechanism is shown actuating rods-82, 84, 86, and 88, otheractuating means may be used such as a motor, various drives, belt andgear arrangements.

When sleeve is converted into open turbine position,

as shown in FIGURE 5, sides 62, 64, 66 and 68 act as vertical bafllesand direct the liquid flow from rotor 40 toward the periphery of themixing vessel, not shown, with great force. Further, the back pressurecaused by these bafiles forces a quantity of liquid to move betweenstator spokes 31 resulting in an excellent mixing effect in the entiremass of liquid with no formation of stagnant pools of liquid within themixing vessel, or a vortex in the liquid.

Sides 62, 64, 66, and 68 are opened to any desired angle, as viewed inFIGURE 5, giving a variety of mixing characteristics. When fully opened,they act as vertical baffles. When partially opened, back pressure isincreased resulting in a greater quantity of liquid moved between thevanes of the stator.

When the sides are in the open position, material adhering to the outersurfaces of sleeve 6%) can be removed since the liquid issuing betweenthe sides, flows past the outer surface of an adjoining side withsulficient force to remove any adhering material. This saves much timeconsuming and messy manual operation.

Another embodiment for rotating sides 62, 64, 66, and 68 of sleeve 60!is shown in FIGURE 6. Coupled to the pivoting mechanism of sides 62, 64,66 and 68 are arms 120, 122, 124, and 126, respectively. Each of arms120, 122, 124, and 126 has a sprocket wheel 128 mounted thereon abovethe upper edges of corresponding sides 62,.

64, 66, and 68. Concentrically disposed about driving shaft 24 is asleeve 139. Sleeve 139 may be journalled in support bracket 12. Mountedon the outer surface of sleeve 130 adjacent its lower end are gear teeth132 for cooperatively mating with sprocket wheels 128. R0- tating sleeve139 will rotate sprocket wheels 128 which in turn rotate arms 120, 122,124, and 126. Sleeve 130 may be rotated in any convenient manner. Ifdesired, gear teeth may be cut in arms 120, 122, 124 and 126, and sleeve130.

Advantageously, material may be introduced down sleeve 136 into themachine or withdrawn. Liquid or comminuted material may be introducedvia shaft 130 and dispersed by centrifugal force by rotor 42 into thestator 30. By this manner, or by reversing the procedure, a close orcoarser relationship of the stator and rotor parts of the operating headmay be accomplished tosele'ctively obtain a finer or coarser granulationof the particles in suspension in the emulsion in the container.

If desired, a baffle plate, not shown, may be adjustably positionedgenerally perpendicular to the axis of shaft 24 and above the operatinghead 20 by suitable means. The baflle plate effectively deflectshorizontally the material surging through the operating head so that thedesired circulation will be established.

It will now be seen that the mixing machine is not only adaptable foruse both as an open or closed turbine mixer, but operates efficientlysince the rotor is shaped to pump material through the operating headwith great may occur to other persons skilled in the art, which might beemployed for various adaptations to other useful purposes within thescope of the invention claimed.

What is claimed is:

1. A mixing device for mixing material within a container comprising amixing head for operation within said container, said mixing headcomprising a stator and a rotor, the stator comprising a central hub anda plurality of 5130 135 radiating therefrom, each of said spokes havinga smooth under-surface inclined upwardly and outwardly and dearelatively sharp angle to the axis of said head, said rotor having aplurality of fan-like blades each tapering upwardly and rearwardly andhaving a pitch substantially corresponding to the angle of saidundersurface of said spokes, the leading and trailing edges of saidblades rotating in a plane substantially parallel to the under-surfacesof said spokes with the leading edge being more remote therefrom thanthe trailing edge, a remote drive shaft for said rotor, a mixer shaftvertically aligned with said drive shaft and having its lower endjournalled in and extending below said stator, said extending end beingconnected to said rotor, means coupling the facing ends of said driveshaft and said mixer shaft, means rotating said drive shaft, meanssupporting said drive shaft, said stator being journalled to said mixingshaft at a predetermined distance fromsaid supporting means, a pluralityof side elements pivotally connected to selected ones of said statorspokes, said sides when in closed position forming an open endedcylindrical sleeve surrounding said stator spokes, and means forpivoting said sides outwardly away from said rotor into open position sothat said mixer can be readily converted a from closed to open turbineoperation.

2. A mixingdevice for mixing material Within. a container comprising amixing head for operation within said container, said mixing headcomprising a stator and a rotor, the stator comprising a central hub anda plurality of spaced apart spokes radiating therefrom, each of saidspokes having a smooth under-surface which is inclined upwardly andoutwardly and defining a relatively sharp angle to the horizontal, saidrotor having a plurality of fan-like blades each taperin 'upwardly andrearwardly and having a pitch substantially corresponding to said angleof the'under-surface of said spokes so that the leading and the trailingedges of said blades rotate in planes substantially parallel to saidunder-surface of said spokes with the leading edges of said blades beingmore remote therefrom than said trailing edges, said trailing edgesbeing in hydraulic shearing relation to said under-surfaces, remotedrive means for said rotor, a shaft connecting said drive means to saidrotor, means journalling said stator on said shaft abovesaid rotor,means coupled to said shaft for moving said shaft longitudinally withrespect to said stator for varying the spacing between said blades ofsaid rotor with the under-surface of said stator, a plurality of sideelements pivotally connected to selected ones of said stator spokes,said side elements when in closed position forming an open endedcylindrical sleeve surrounding said stator spokes and means for pivotingsaid side elements outwardly away from said rotor into open position sothat said mixer can be readily converted from closed to open turbineoperation.

3. A mixing device for mixing material within a container comprising amixing head for operation within said container, said mixing headcomprising a stator and a rotor, the stator comprising a central hub anda plurality of spaced apart spokes radiating therefrom, each of saidspokes having a smooth under-surface which is inclined upwardly andoutwardly and defining a relatively sharp angle to the horizontal, saidrotor having a plurality of fan-like blades each tapering upwardly andrearwardly and having a pitch substantially corresponding to said angleof the under-surface of said spokes so that the leading and the trailingedges of said blades rotate in planes substantially parallel to saidunder-surfaceof said spokes, with the leading edges of said blades beingmore remote remote drive means'for said rotor, a shaft connecting saiddrive means to said rotor, means journalling said stator on said shaftabove said rotor, a plurality of side elements pivotally connected toselected ones of said stator spokes, said sides when in closed positionforming an open ended sleeve surrounding said stator spokes and meansfor pivoting said sides outwardly away from said rotor into openposition so that said mixer can be readily converted from closed to openturbine operation.

4. In a machine for mixing liquids in a container, comprising drivingmeans, an operating head coupled to said driving means by a shaft, saidhead including a stator, and a rotor, the stator being supported in afixed horizontal position with respect to said driving means and remotetherefrom, and comprising a central hub part and a plurality of spokesradiating therefrom, and being open ended, said shaft havingits lowerend journalled in and extending below said stator and having said rotorattached thereto, said stator spokes having fiat under-surfaces inclinedupwardly in an outward directiondefining a'relatively sharp angle to thehorizontal, and said rotor constituting a plurality of flat fan-likeblades having a pitch substantially corresponding to the angle of thesaid under-surface of the stator spokes, so that the leading and thetrailing edges of said blades rotate in a plane sub-' stantiallyparallel with said under surfaces with said leading edges relativelyremote therefrom, and the trailing edges in hydraulic shearing relationthereto, and an adjustable open ended cylindrical sleeve surroundingsaid stator spokes, said sleeve comprising a plurality of sections eachhingedly connected to selected spokes and adapted to enclose the spacebetween consecutive spokes when in the closed position, said sectionsbeing pivotable generally radially to open position, and actuating meansfor pivoting said sections, said actuating means being remote from saidsections.

5. A mixing device for mixing material within a container comprising amixing head for operation within a container, said mixing headcomprising a stator shell and a rotor having a blade within said statorshell, said stator shell having a plurality of pivotable sections,remote drive means for said rotor, a drive shaft connecting said drivemeans to said rotor and means for pivoting said sections of said statorshell relative to said rotor so that said mixer can be readily convertedfrom closed to open turbine operation.

6. A mixing device for mixing material within a container comprising amixing head for operation within a container, said mixing headcomprising a stator shell and a rotor having a blade cooperativelypositioned with repect to said stator shell, said stator shell having aplurality of pivotable slides, remote drive means for said rotor, adrive shaft connecting'said drive means to said rotor, gear teethoperatively connected to each of said sides of said stator shell anddisposed concentrically about said drive shaft, said sides beingpivotable when said gear teeth are rotated, a hollow shaftconcentrically and rotatably mounted about said drive shaft, and havinggear teeth about its outer surface, said gear teeth cooperativelyengaging each of said first mentioned gear teeth, and means remote fromsaid mixing head for rotating said hollow shaft and pivoting saidsidesrelative to said rotor so that said mixer can be readilyconvertedfrom closed to open turbine operation.

7. A mixing device for mixing material within a container comprising amixing head for operation within therefrom than said trailing edges,said trailing edges being in hydraulic shearing relation to saidunder-surfaces,

a container, said mixing head comprising 'astator shell and a rotorhaving a blade cooperatively positioned with respect to said statorshell, said' stator shell, having a plurality of pivotable sides, remotedrive means for said rotor, a drive shaft connecting said drive'means'to said rotor, a gear wheel coupled to each of said sides, saidsides being pivotable when said gear Wheels are rotated,

and means for rotating said gear wheels in the same direction andpivoting said sides relative to 'said rotor, so that and a rotor havingaiblade cooperatively positioned with respect to said stator shell, saidstator shell having a plurality of pivotable sections, remote drivemeans for said rotor, a drive shaft connecting said drive means to saidrotor and means for pivoting said sections of said stator shell relativeto said rotor to a'selected angle with respect to the axis of saidstator shell, so that said mixer can be converted from closed to adesired open turbine operation.

9. A' mixing device for mixing material within a con tainer comprising amixing head for operation Within a g container, said mixing headcomprising a stator shell and a rotor having a blade cooperativelypositioned with respect to said stator shell, said stator shell having aplurality of pivotable sections, remote drive means for said rotor, adrive shaft connecting said drive means to said rotor and means forpivoting said sections of said stator shell relative to said rotor sothat said mixer can be readily converted from closed to open turbineoperation.

References Qited in the file of this patent UNITED STATES PATENTS861,893 Pool July 30, 1907 1,733,244 Smith Oct. 29, 1929

9. A MIXING DEVICE FOR MIXING MATERIAL WITHIN A CONTAINER COMPRISING AMIXING HEAD FOR OPERATION WITHIN A CONTAINER, SAID MIXING HEADCOMPRISING A STATOR SHELL AND A ROTOR HAVING A BLADE COOPERATIVELYPOSITIONED WITH RESPECT TO SAID STATOR SHELL, SAID STATOR SHELL HAVING APLURALITY OF PIVOTABLE SECTIONS, REMOTE DRIVE MEANS FOR SAID ROTOR, ADRIVE SHAFT CONNECTING SAID DRIVE MEANS TO SAID ROTOR AND MEANS FORPIVOTING SAID SECTIONS OF SAID STATOR SHELL RELATIVE TO SAID ROTOR SOTHAT SAID MIXER CAN BE READILY CONVERTED FROM CLOSED TO OPEN TURBINEOPERATION.